This study will evaluate the effectiveness of a comprehensive intervention program that targets the health care delivery system (primary care providers, nurses, administrative/clerical staff) that provides primary care services to members of a large, non-staff model, managed care health plan (CaliforniaCare HMO). The goal for the intervention program will be to increase colorectal cancer screening rates with fecal occult blood testing (FOBT) and flexible sigmoidoscopy in men and women age greater than or equal to 50 years who are enrolled in the health plan. We have initiated a mailed survey of all CaliforniaCare Medical Groups (N=174) that examines current colorectal cancer screening practices. Using this survey, we will select a sample of Study Medical Groups (N=32) based on specific study eligibility criteria. Prior to the intervention, we will perform a telephone survey of a random sample (N=416) of CaliforniaCare health plan members drawn from the Study Medical Groups to assess baseline rates of screening for colorectal cancer (FOBT in past 12 months; sigmoidoscopy in past 3 years), as well as perceived barriers to and facilitators of screening. Using a randomized, controlled design, the Study Medical Groups will be assigned to either the Control or Intervention condition. The Intervention will be delivered and reinforced over a two year period, allowing sufficient time for institutionalization of all of its components, as well as for exposure of HMO members to the opportunity to receive a screening test. Following that time, we will perform a second telephone survey of another independent random sample of members (N=1088) enrolled in the Study Medical Groups. The main outcome will be a comparison of screening rates (FOBT and sigmoidoscopy) in members drawn from the Control and Intervention Study Medical Groups. As a process measure, we will survey primary care providers from the Study Medical Groups prior to randomization and intervention, and during the follow-up period two years after the initiation of the intervention (final sample N=500 providers). Additional secondary analyses will examine research questions that explore the importance of the Health Services Utilization Framework variables in increasing colorectal cancer screening rates among Intervention versus Control condition members. Finally, we will establish the validity of member self-report of FOBT and sigmoidoscopy through a chart review.